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gitea/vendor/github.com/blevesearch/zapx/v11/new.go
2021-02-28 18:08:33 -05:00

817 lines
20 KiB
Go
Vendored

// Copyright (c) 2018 Couchbase, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package zap
import (
"bytes"
"encoding/binary"
"math"
"sort"
"sync"
"github.com/RoaringBitmap/roaring"
index "github.com/blevesearch/bleve_index_api"
segment "github.com/blevesearch/scorch_segment_api/v2"
"github.com/blevesearch/vellum"
"github.com/golang/snappy"
)
var NewSegmentBufferNumResultsBump int = 100
var NewSegmentBufferNumResultsFactor float64 = 1.0
var NewSegmentBufferAvgBytesPerDocFactor float64 = 1.0
// ValidateDocFields can be set by applications to perform additional checks
// on fields in a document being added to a new segment, by default it does
// nothing.
// This API is experimental and may be removed at any time.
var ValidateDocFields = func(field index.Field) error {
return nil
}
var defaultChunkFactor uint32 = 1024
// New creates an in-memory zap-encoded SegmentBase from a set of Documents
func (z *ZapPlugin) New(results []index.Document) (
segment.Segment, uint64, error) {
return z.newWithChunkFactor(results, defaultChunkFactor)
}
func (*ZapPlugin) newWithChunkFactor(results []index.Document,
chunkFactor uint32) (segment.Segment, uint64, error) {
s := interimPool.Get().(*interim)
var br bytes.Buffer
if s.lastNumDocs > 0 {
// use previous results to initialize the buf with an estimate
// size, but note that the interim instance comes from a
// global interimPool, so multiple scorch instances indexing
// different docs can lead to low quality estimates
estimateAvgBytesPerDoc := int(float64(s.lastOutSize/s.lastNumDocs) *
NewSegmentBufferNumResultsFactor)
estimateNumResults := int(float64(len(results)+NewSegmentBufferNumResultsBump) *
NewSegmentBufferAvgBytesPerDocFactor)
br.Grow(estimateAvgBytesPerDoc * estimateNumResults)
}
s.results = results
s.chunkFactor = chunkFactor
s.w = NewCountHashWriter(&br)
storedIndexOffset, fieldsIndexOffset, fdvIndexOffset, dictOffsets,
err := s.convert()
if err != nil {
return nil, uint64(0), err
}
sb, err := InitSegmentBase(br.Bytes(), s.w.Sum32(), chunkFactor,
s.FieldsMap, s.FieldsInv, uint64(len(results)),
storedIndexOffset, fieldsIndexOffset, fdvIndexOffset, dictOffsets)
if err == nil && s.reset() == nil {
s.lastNumDocs = len(results)
s.lastOutSize = len(br.Bytes())
interimPool.Put(s)
}
return sb, uint64(len(br.Bytes())), err
}
var interimPool = sync.Pool{New: func() interface{} { return &interim{} }}
// interim holds temporary working data used while converting from
// analysis results to a zap-encoded segment
type interim struct {
results []index.Document
chunkFactor uint32
w *CountHashWriter
// FieldsMap adds 1 to field id to avoid zero value issues
// name -> field id + 1
FieldsMap map[string]uint16
// FieldsInv is the inverse of FieldsMap
// field id -> name
FieldsInv []string
// Term dictionaries for each field
// field id -> term -> postings list id + 1
Dicts []map[string]uint64
// Terms for each field, where terms are sorted ascending
// field id -> []term
DictKeys [][]string
// Fields whose IncludeDocValues is true
// field id -> bool
IncludeDocValues []bool
// postings id -> bitmap of docNums
Postings []*roaring.Bitmap
// postings id -> freq/norm's, one for each docNum in postings
FreqNorms [][]interimFreqNorm
freqNormsBacking []interimFreqNorm
// postings id -> locs, one for each freq
Locs [][]interimLoc
locsBacking []interimLoc
numTermsPerPostingsList []int // key is postings list id
numLocsPerPostingsList []int // key is postings list id
builder *vellum.Builder
builderBuf bytes.Buffer
metaBuf bytes.Buffer
tmp0 []byte
tmp1 []byte
lastNumDocs int
lastOutSize int
}
func (s *interim) reset() (err error) {
s.results = nil
s.chunkFactor = 0
s.w = nil
s.FieldsMap = nil
s.FieldsInv = nil
for i := range s.Dicts {
s.Dicts[i] = nil
}
s.Dicts = s.Dicts[:0]
for i := range s.DictKeys {
s.DictKeys[i] = s.DictKeys[i][:0]
}
s.DictKeys = s.DictKeys[:0]
for i := range s.IncludeDocValues {
s.IncludeDocValues[i] = false
}
s.IncludeDocValues = s.IncludeDocValues[:0]
for _, idn := range s.Postings {
idn.Clear()
}
s.Postings = s.Postings[:0]
s.FreqNorms = s.FreqNorms[:0]
for i := range s.freqNormsBacking {
s.freqNormsBacking[i] = interimFreqNorm{}
}
s.freqNormsBacking = s.freqNormsBacking[:0]
s.Locs = s.Locs[:0]
for i := range s.locsBacking {
s.locsBacking[i] = interimLoc{}
}
s.locsBacking = s.locsBacking[:0]
s.numTermsPerPostingsList = s.numTermsPerPostingsList[:0]
s.numLocsPerPostingsList = s.numLocsPerPostingsList[:0]
s.builderBuf.Reset()
if s.builder != nil {
err = s.builder.Reset(&s.builderBuf)
}
s.metaBuf.Reset()
s.tmp0 = s.tmp0[:0]
s.tmp1 = s.tmp1[:0]
s.lastNumDocs = 0
s.lastOutSize = 0
return err
}
func (s *interim) grabBuf(size int) []byte {
buf := s.tmp0
if cap(buf) < size {
buf = make([]byte, size)
s.tmp0 = buf
}
return buf[0:size]
}
type interimStoredField struct {
vals [][]byte
typs []byte
arrayposs [][]uint64 // array positions
}
type interimFreqNorm struct {
freq uint64
norm float32
numLocs int
}
type interimLoc struct {
fieldID uint16
pos uint64
start uint64
end uint64
arrayposs []uint64
}
func (s *interim) convert() (uint64, uint64, uint64, []uint64, error) {
s.FieldsMap = map[string]uint16{}
s.getOrDefineField("_id") // _id field is fieldID 0
for _, result := range s.results {
result.VisitComposite(func(field index.CompositeField) {
s.getOrDefineField(field.Name())
})
result.VisitFields(func(field index.Field) {
s.getOrDefineField(field.Name())
})
}
sort.Strings(s.FieldsInv[1:]) // keep _id as first field
for fieldID, fieldName := range s.FieldsInv {
s.FieldsMap[fieldName] = uint16(fieldID + 1)
}
if cap(s.IncludeDocValues) >= len(s.FieldsInv) {
s.IncludeDocValues = s.IncludeDocValues[:len(s.FieldsInv)]
} else {
s.IncludeDocValues = make([]bool, len(s.FieldsInv))
}
s.prepareDicts()
for _, dict := range s.DictKeys {
sort.Strings(dict)
}
s.processDocuments()
storedIndexOffset, err := s.writeStoredFields()
if err != nil {
return 0, 0, 0, nil, err
}
var fdvIndexOffset uint64
var dictOffsets []uint64
if len(s.results) > 0 {
fdvIndexOffset, dictOffsets, err = s.writeDicts()
if err != nil {
return 0, 0, 0, nil, err
}
} else {
dictOffsets = make([]uint64, len(s.FieldsInv))
}
fieldsIndexOffset, err := persistFields(s.FieldsInv, s.w, dictOffsets)
if err != nil {
return 0, 0, 0, nil, err
}
return storedIndexOffset, fieldsIndexOffset, fdvIndexOffset, dictOffsets, nil
}
func (s *interim) getOrDefineField(fieldName string) int {
fieldIDPlus1, exists := s.FieldsMap[fieldName]
if !exists {
fieldIDPlus1 = uint16(len(s.FieldsInv) + 1)
s.FieldsMap[fieldName] = fieldIDPlus1
s.FieldsInv = append(s.FieldsInv, fieldName)
s.Dicts = append(s.Dicts, make(map[string]uint64))
n := len(s.DictKeys)
if n < cap(s.DictKeys) {
s.DictKeys = s.DictKeys[:n+1]
s.DictKeys[n] = s.DictKeys[n][:0]
} else {
s.DictKeys = append(s.DictKeys, []string(nil))
}
}
return int(fieldIDPlus1 - 1)
}
// fill Dicts and DictKeys from analysis results
func (s *interim) prepareDicts() {
var pidNext int
var totTFs int
var totLocs int
visitField := func(field index.Field) {
fieldID := uint16(s.getOrDefineField(field.Name()))
dict := s.Dicts[fieldID]
dictKeys := s.DictKeys[fieldID]
tfs := field.AnalyzedTokenFrequencies()
for term, tf := range tfs {
pidPlus1, exists := dict[term]
if !exists {
pidNext++
pidPlus1 = uint64(pidNext)
dict[term] = pidPlus1
dictKeys = append(dictKeys, term)
s.numTermsPerPostingsList = append(s.numTermsPerPostingsList, 0)
s.numLocsPerPostingsList = append(s.numLocsPerPostingsList, 0)
}
pid := pidPlus1 - 1
s.numTermsPerPostingsList[pid] += 1
s.numLocsPerPostingsList[pid] += len(tf.Locations)
totLocs += len(tf.Locations)
}
totTFs += len(tfs)
s.DictKeys[fieldID] = dictKeys
}
for _, result := range s.results {
// walk each composite field
result.VisitComposite(func(field index.CompositeField) {
visitField(field)
})
// walk each field
result.VisitFields(visitField)
}
numPostingsLists := pidNext
if cap(s.Postings) >= numPostingsLists {
s.Postings = s.Postings[:numPostingsLists]
} else {
postings := make([]*roaring.Bitmap, numPostingsLists)
copy(postings, s.Postings[:cap(s.Postings)])
for i := 0; i < numPostingsLists; i++ {
if postings[i] == nil {
postings[i] = roaring.New()
}
}
s.Postings = postings
}
if cap(s.FreqNorms) >= numPostingsLists {
s.FreqNorms = s.FreqNorms[:numPostingsLists]
} else {
s.FreqNorms = make([][]interimFreqNorm, numPostingsLists)
}
if cap(s.freqNormsBacking) >= totTFs {
s.freqNormsBacking = s.freqNormsBacking[:totTFs]
} else {
s.freqNormsBacking = make([]interimFreqNorm, totTFs)
}
freqNormsBacking := s.freqNormsBacking
for pid, numTerms := range s.numTermsPerPostingsList {
s.FreqNorms[pid] = freqNormsBacking[0:0]
freqNormsBacking = freqNormsBacking[numTerms:]
}
if cap(s.Locs) >= numPostingsLists {
s.Locs = s.Locs[:numPostingsLists]
} else {
s.Locs = make([][]interimLoc, numPostingsLists)
}
if cap(s.locsBacking) >= totLocs {
s.locsBacking = s.locsBacking[:totLocs]
} else {
s.locsBacking = make([]interimLoc, totLocs)
}
locsBacking := s.locsBacking
for pid, numLocs := range s.numLocsPerPostingsList {
s.Locs[pid] = locsBacking[0:0]
locsBacking = locsBacking[numLocs:]
}
}
func (s *interim) processDocuments() {
numFields := len(s.FieldsInv)
reuseFieldLens := make([]int, numFields)
reuseFieldTFs := make([]index.TokenFrequencies, numFields)
for docNum, result := range s.results {
for i := 0; i < numFields; i++ { // clear these for reuse
reuseFieldLens[i] = 0
reuseFieldTFs[i] = nil
}
s.processDocument(uint64(docNum), result,
reuseFieldLens, reuseFieldTFs)
}
}
func (s *interim) processDocument(docNum uint64,
result index.Document,
fieldLens []int, fieldTFs []index.TokenFrequencies) {
visitField := func(field index.Field) {
fieldID := uint16(s.getOrDefineField(field.Name()))
fieldLens[fieldID] += field.AnalyzedLength()
existingFreqs := fieldTFs[fieldID]
if existingFreqs != nil {
existingFreqs.MergeAll(field.Name(), field.AnalyzedTokenFrequencies())
} else {
fieldTFs[fieldID] = field.AnalyzedTokenFrequencies()
}
}
// walk each composite field
result.VisitComposite(func(field index.CompositeField) {
visitField(field)
})
// walk each field
result.VisitFields(visitField)
// now that it's been rolled up into fieldTFs, walk that
for fieldID, tfs := range fieldTFs {
dict := s.Dicts[fieldID]
norm := float32(1.0 / math.Sqrt(float64(fieldLens[fieldID])))
for term, tf := range tfs {
pid := dict[term] - 1
bs := s.Postings[pid]
bs.Add(uint32(docNum))
s.FreqNorms[pid] = append(s.FreqNorms[pid],
interimFreqNorm{
freq: uint64(tf.Frequency()),
norm: norm,
numLocs: len(tf.Locations),
})
if len(tf.Locations) > 0 {
locs := s.Locs[pid]
for _, loc := range tf.Locations {
var locf = uint16(fieldID)
if loc.Field != "" {
locf = uint16(s.getOrDefineField(loc.Field))
}
var arrayposs []uint64
if len(loc.ArrayPositions) > 0 {
arrayposs = loc.ArrayPositions
}
locs = append(locs, interimLoc{
fieldID: locf,
pos: uint64(loc.Position),
start: uint64(loc.Start),
end: uint64(loc.End),
arrayposs: arrayposs,
})
}
s.Locs[pid] = locs
}
}
}
}
func (s *interim) writeStoredFields() (
storedIndexOffset uint64, err error) {
varBuf := make([]byte, binary.MaxVarintLen64)
metaEncode := func(val uint64) (int, error) {
wb := binary.PutUvarint(varBuf, val)
return s.metaBuf.Write(varBuf[:wb])
}
data, compressed := s.tmp0[:0], s.tmp1[:0]
defer func() { s.tmp0, s.tmp1 = data, compressed }()
// keyed by docNum
docStoredOffsets := make([]uint64, len(s.results))
// keyed by fieldID, for the current doc in the loop
docStoredFields := map[uint16]interimStoredField{}
for docNum, result := range s.results {
for fieldID := range docStoredFields { // reset for next doc
delete(docStoredFields, fieldID)
}
var validationErr error
result.VisitFields(func(field index.Field) {
fieldID := uint16(s.getOrDefineField(field.Name()))
if field.Options().IsStored() {
isf := docStoredFields[fieldID]
isf.vals = append(isf.vals, field.Value())
isf.typs = append(isf.typs, field.EncodedFieldType())
isf.arrayposs = append(isf.arrayposs, field.ArrayPositions())
docStoredFields[fieldID] = isf
}
if field.Options().IncludeDocValues() {
s.IncludeDocValues[fieldID] = true
}
err := ValidateDocFields(field)
if err != nil && validationErr == nil {
validationErr = err
}
})
if validationErr != nil {
return 0, validationErr
}
var curr int
s.metaBuf.Reset()
data = data[:0]
// _id field special case optimizes ExternalID() lookups
idFieldVal := docStoredFields[uint16(0)].vals[0]
_, err = metaEncode(uint64(len(idFieldVal)))
if err != nil {
return 0, err
}
// handle non-"_id" fields
for fieldID := 1; fieldID < len(s.FieldsInv); fieldID++ {
isf, exists := docStoredFields[uint16(fieldID)]
if exists {
curr, data, err = persistStoredFieldValues(
fieldID, isf.vals, isf.typs, isf.arrayposs,
curr, metaEncode, data)
if err != nil {
return 0, err
}
}
}
metaBytes := s.metaBuf.Bytes()
compressed = snappy.Encode(compressed[:cap(compressed)], data)
docStoredOffsets[docNum] = uint64(s.w.Count())
_, err := writeUvarints(s.w,
uint64(len(metaBytes)),
uint64(len(idFieldVal)+len(compressed)))
if err != nil {
return 0, err
}
_, err = s.w.Write(metaBytes)
if err != nil {
return 0, err
}
_, err = s.w.Write(idFieldVal)
if err != nil {
return 0, err
}
_, err = s.w.Write(compressed)
if err != nil {
return 0, err
}
}
storedIndexOffset = uint64(s.w.Count())
for _, docStoredOffset := range docStoredOffsets {
err = binary.Write(s.w, binary.BigEndian, docStoredOffset)
if err != nil {
return 0, err
}
}
return storedIndexOffset, nil
}
func (s *interim) writeDicts() (fdvIndexOffset uint64, dictOffsets []uint64, err error) {
dictOffsets = make([]uint64, len(s.FieldsInv))
fdvOffsetsStart := make([]uint64, len(s.FieldsInv))
fdvOffsetsEnd := make([]uint64, len(s.FieldsInv))
buf := s.grabBuf(binary.MaxVarintLen64)
tfEncoder := newChunkedIntCoder(uint64(s.chunkFactor), uint64(len(s.results)-1))
locEncoder := newChunkedIntCoder(uint64(s.chunkFactor), uint64(len(s.results)-1))
fdvEncoder := newChunkedContentCoder(uint64(s.chunkFactor), uint64(len(s.results)-1), s.w, false)
var docTermMap [][]byte
if s.builder == nil {
s.builder, err = vellum.New(&s.builderBuf, nil)
if err != nil {
return 0, nil, err
}
}
for fieldID, terms := range s.DictKeys {
if cap(docTermMap) < len(s.results) {
docTermMap = make([][]byte, len(s.results))
} else {
docTermMap = docTermMap[0:len(s.results)]
for docNum := range docTermMap { // reset the docTermMap
docTermMap[docNum] = docTermMap[docNum][:0]
}
}
dict := s.Dicts[fieldID]
for _, term := range terms { // terms are already sorted
pid := dict[term] - 1
postingsBS := s.Postings[pid]
freqNorms := s.FreqNorms[pid]
freqNormOffset := 0
locs := s.Locs[pid]
locOffset := 0
postingsItr := postingsBS.Iterator()
for postingsItr.HasNext() {
docNum := uint64(postingsItr.Next())
freqNorm := freqNorms[freqNormOffset]
err = tfEncoder.Add(docNum,
encodeFreqHasLocs(freqNorm.freq, freqNorm.numLocs > 0),
uint64(math.Float32bits(freqNorm.norm)))
if err != nil {
return 0, nil, err
}
if freqNorm.numLocs > 0 {
numBytesLocs := 0
for _, loc := range locs[locOffset : locOffset+freqNorm.numLocs] {
numBytesLocs += totalUvarintBytes(
uint64(loc.fieldID), loc.pos, loc.start, loc.end,
uint64(len(loc.arrayposs)), loc.arrayposs)
}
err = locEncoder.Add(docNum, uint64(numBytesLocs))
if err != nil {
return 0, nil, err
}
for _, loc := range locs[locOffset : locOffset+freqNorm.numLocs] {
err = locEncoder.Add(docNum,
uint64(loc.fieldID), loc.pos, loc.start, loc.end,
uint64(len(loc.arrayposs)))
if err != nil {
return 0, nil, err
}
err = locEncoder.Add(docNum, loc.arrayposs...)
if err != nil {
return 0, nil, err
}
}
locOffset += freqNorm.numLocs
}
freqNormOffset++
docTermMap[docNum] = append(
append(docTermMap[docNum], term...),
termSeparator)
}
tfEncoder.Close()
locEncoder.Close()
postingsOffset, err :=
writePostings(postingsBS, tfEncoder, locEncoder, nil, s.w, buf)
if err != nil {
return 0, nil, err
}
if postingsOffset > uint64(0) {
err = s.builder.Insert([]byte(term), postingsOffset)
if err != nil {
return 0, nil, err
}
}
tfEncoder.Reset()
locEncoder.Reset()
}
err = s.builder.Close()
if err != nil {
return 0, nil, err
}
// record where this dictionary starts
dictOffsets[fieldID] = uint64(s.w.Count())
vellumData := s.builderBuf.Bytes()
// write out the length of the vellum data
n := binary.PutUvarint(buf, uint64(len(vellumData)))
_, err = s.w.Write(buf[:n])
if err != nil {
return 0, nil, err
}
// write this vellum to disk
_, err = s.w.Write(vellumData)
if err != nil {
return 0, nil, err
}
// reset vellum for reuse
s.builderBuf.Reset()
err = s.builder.Reset(&s.builderBuf)
if err != nil {
return 0, nil, err
}
// write the field doc values
if s.IncludeDocValues[fieldID] {
for docNum, docTerms := range docTermMap {
if len(docTerms) > 0 {
err = fdvEncoder.Add(uint64(docNum), docTerms)
if err != nil {
return 0, nil, err
}
}
}
err = fdvEncoder.Close()
if err != nil {
return 0, nil, err
}
fdvOffsetsStart[fieldID] = uint64(s.w.Count())
_, err = fdvEncoder.Write()
if err != nil {
return 0, nil, err
}
fdvOffsetsEnd[fieldID] = uint64(s.w.Count())
fdvEncoder.Reset()
} else {
fdvOffsetsStart[fieldID] = fieldNotUninverted
fdvOffsetsEnd[fieldID] = fieldNotUninverted
}
}
fdvIndexOffset = uint64(s.w.Count())
for i := 0; i < len(fdvOffsetsStart); i++ {
n := binary.PutUvarint(buf, fdvOffsetsStart[i])
_, err := s.w.Write(buf[:n])
if err != nil {
return 0, nil, err
}
n = binary.PutUvarint(buf, fdvOffsetsEnd[i])
_, err = s.w.Write(buf[:n])
if err != nil {
return 0, nil, err
}
}
return fdvIndexOffset, dictOffsets, nil
}
// returns the total # of bytes needed to encode the given uint64's
// into binary.PutUVarint() encoding
func totalUvarintBytes(a, b, c, d, e uint64, more []uint64) (n int) {
n = numUvarintBytes(a)
n += numUvarintBytes(b)
n += numUvarintBytes(c)
n += numUvarintBytes(d)
n += numUvarintBytes(e)
for _, v := range more {
n += numUvarintBytes(v)
}
return n
}
// returns # of bytes needed to encode x in binary.PutUvarint() encoding
func numUvarintBytes(x uint64) (n int) {
for x >= 0x80 {
x >>= 7
n++
}
return n + 1
}